Giant plant! Caudex 40
centimetres in diameter, stems the same in length.

A cut through (not made by
me), show the perfect ants nest.

I found this member of the
Rubiaceae family in 2-400 meters height on
Mt Soputan on Sulawesi in Indonesia. It grows on the stems of trees
in rather open areas receiving quite some water in the wet months.
It tend to sit underneath the canopy, protected from the direct sum.
The caudex starts our smooth, but will develop thin spines up to two
centimetres, almost resembling hairs on old plants. The caudex can
grow to at least 40 centimetres in diameter with several stems.
These stems can reach at least 50 centimetres. The tiny white
flowers are, as for other Myrmecodias, develop in holes in
the stem. The caudex are, as seen below, a perfect ants nest, and
all plants I found had ants inside them.